Wire belts are commonly used for conveying articles during cooling, drying, coating, cooking and many other applications. In one particular application, wire belts are used to convey food articles during cooking or processing of the food. Wire belts are advantageous for food processing because they provide an open, flow-through mesh, a high degree of flexibility, a sanitary construction, simple installation and maintenance, and the ability to be positively driven. As the demands of production increase, however, the number of articles conveyed must be increased and the wire belt must support heavier loads and be driven faster, resulting in an increased strain on the wire belts. Existing wire belts have been unable to handle the increased production requirements.
Existing wire belts 10, FIG. 1, are typically made of interlocking wire links 12 that form the open mesh and provide a flexible belt that is suited to the above applications. The wire links 12 of existing wire belts 10 include linking portions 14 that are interlocked or linked with linking portions 14 of an adjacent wire link 12. The interlocked linking portions 14 form a number of joints 16 and open spaces 18 in the wire belt 10. The open spaces 18 are defined by the distance between the wire links 12, known as the "pitch" (P), and the "spacing width" (A) of the locking portions 14. The "mesh" of a wire belt 10 is defined as the combination of the pitch P and wire diameter.
The belt strength of wire belts is primarily determined by the sum of the cross-sectional area of the wires doing the pulling, i.e. the number of joints 16. Possible ways of increasing the strength of existing wire belts include using a larger diameter wire, using a stronger wire (e.g., higher tensile strength or stronger materials) and/or increasing the number of joints 16 that do the pulling. Because of the limitations on the "spacing width" (A) and "mesh" (pitch (P) and wire diameter) in existing wire belts, these approaches to increasing belt strength are not practical.
To form a wire belt 10 the wire links 12 must be interlocked, e.g., by weaving each wire link 12 with an adjacent wire link 12 into the wire belt 10. Increasing the diameter of the wire links 12 decreases the flexibility of the wire links 12 and makes interlocking of the wires difficult, resulting in an inflexible and/or distorted wire belt. Increasing the strength of the wire material may increase the "brittleness" of wire links 12 making them susceptible to cracking when the wire link 12 is formed.
Increasing the number of joints in a wire belt 10 of a given width requires decreasing the "spacing width" (A) of the linking portions 14. For a given mesh, decreasing the "spacing width" (A) is not possible beyond a minimum width which allows the wire links 12 to be interlocked without causing the wire to bend in a radius surpassing the yield strength of the wire. Merely decreasing the "spacing width" (A) of linking portions 14 to increase the number of joints would therefore cause permanent deformation in the wire links and a distorted wire belt.
Accordingly, what is needed is a wire belt having an increased belt strength to provide added product support and prevents articles from falling through the mesh of the wire belt. What is also needed is a method for increasing the strength of the wire belt by increasing the number of joints without having to increase the diameter or material of the wire link and without resulting in deformed wire links and a distorted and inflexible wire belt.